A homosexual who has the unreasonable fear that somewhere, sometime, someone may be having heterosexual intercourse. And enjoying it.

Proud Labour Conservative is the current personification of a Heterophobe, as he has a complete fear of heterosexuals. But he also has a complete fear of using his own name.
And, for some reason, he attacks conservatives and Bush officials as homosexual.

heterophobe- one who has an irrational fear or hatred of those that lead the heterosexual lifestyle.

Cecil, an avowed heterophobe, pointed to a couple in the distance, "See Arthur, see them, nasty breeders, what right do they have to be at a pride march" he sighed, "Filthy, Filthy, they look like the Cleavers, oh look(he points to a child running with a ball), see, look, theres Wally, now where's the "Beave"?